For me 6 weeks total rest helped a bit. Then started to play again and the tendon got inflamed. Now, 3 months later, after loads of exercises/stretching by a physiotherapist i am able to play again. but still mis 10% of my motion in both ways.

2 tips.

- make sure you really dont stop using your arm. so get that cup, do the laundry etc. worst effect will be that you develop an minor/major frozen shoulder. then you are even further away from the tennis court.

- icing, but also ibrupofin or something when it inflames. without any hesitation. it leads to impingement and that is really nasty..

And tennis with that shoulder should not happen until the above exercises can be done without pain.

As to using your left hand - many here have done it rather than waiting through the whole process.
(The frustrating thing is that it is takes an awful long time to be anywhere near as good as with your dominant hand.)

Consider if you have impingement AND the tissue at that location is also swollen.

When I had a supraspinatus tear on my non-tennis arm, a physical therapist looked at my shoulder posture and selected light shoulder exercises to improve the position/posture of my shoulder blade/scapula. He carefully supervised how I did the exercises. I believe, but do not know, that I injured my supraspinatus at the gym by using too much weight for the well-known rotator cuff preventive exercise - external shoulder rotations. I did not understand that these are lighter weight exercises. I was using 25 lbs and more on pulleys. Now, I use light resistance bands (Theraband yellow).

Be sure to understand this Todd Ellenbecker video on the shoulder and impingement risks for serving. There is a shorter video by Jim MaClellan but this one has the details plus preventive conditioning.

Consider if you have impingement AND the tissue at that location is also swollen.

When I had a supraspinatus tear on my non-tennis arm, a physical therapist looked at my shoulder posture and selected light shoulder exercises to improve the position/posture of my shoulder blade/scapula. He carefully supervised how I did the exercises. I believe, but do not know, that I injured my supraspinatus at the gym by using too much weight for the well-known rotator cuff preventive exercise - external shoulder rotations. I did not understand that these are lighter weight exercises. I was using 25 lbs and more on pulleys. Now, I use light resistance bands (Theraband yellow).

I had bursitis before and it was really really bad... I had to stop from playing tennis and biking, which was depressing. I've tried different medications and consulted to different doctors. I was told by my coach to go for stem cell treatment, which I tried with my orthopedic surgeon, Dr Grossman. The therapy went fine and it was more than a year now, never felt pain on my right shoulder again..